1 files changed, 38 insertions, 0 deletions
diff --git a/src/output.js b/src/output.js
new file mode 100644
index 0000000..5ab9375
--- /dev/null
+++ b/src/output.js
@@ -0,0 +1,38 @@
+import fs from 'node:fs';
+import { WaError } from './rpc.js';
+import { format } from './format/index.js';
+
+// Parses --params / --json: literal JSON, @file or - (stdin).
+export function parseJsonArg(value, flag) {
+    if (value === undefined) return {};
+    let text = value;
+    try {
+        if (value === '-') text = fs.readFileSync(0, 'utf8');
+        else if (value.startsWith('@')) text = fs.readFileSync(value.slice(1), 'utf8');
+    } catch (e) {
+        throw new WaError('EINVAL', `${flag}: ${e.message}`);
+    }
+    try {
+        return JSON.parse(text);
+    } catch (e) {
+        throw new WaError('EINVAL', `${flag}: invalid JSON (${e.message})`);
+    }
+}
+
+export function print(data, fmt = 'json', { columns, output } = {}) {
+    let text;
+    try {
+        text = format(data, fmt, { columns });
+    } catch (e) {
+        throw new WaError(e.code || 'EINVAL', e.message);
+    }
+    if (output) {
+        fs.writeFileSync(output, text ? `${text}\n` : '');
+    } else if (text) {
+        process.stdout.write(`${text}\n`);
+    }
+}
+
+export function readStdin() {
+    return fs.readFileSync(0, 'utf8').replace(/\n$/, '');
+}